Chapter 1The Basics of Biology

What causes it to

rain?

What causes

lightning?

What causes a tornado?

1-1 What is Science?• An organized approach to figuring

out why something happens– Make an observation– Gathering data– Experiment

• Involves inference – a logical interpretation based on prior knowledge or experience

The Bean• “No! The bean

is not alive”.• “Yes, the bean is

alive when you put it in soil”.

• “Yes. The bean is alive in the bag”.

1-3 Studying Life

• If Biology is the study of living things… how do we know what is living & what isn't?????

Characteristics of Living Things

1. Respond to their environment2. Made up of units called cells3. Obtain & Use Energy4. Grow & Develop5. Reproduce6. Based on a universal genetic code = DNA7. Taken as a group, change over time8. Maintain a stable internal environment

Respond to their environment

• Stimulus – an outside signal

Made up of units called cells• Cell = small self-

contained unit– Barrier separates it

from surroundings• Unicellular –

organism made up of only one cell– Ex: Bacteria, protists

• Multicellular – organism made up of two or more cells– Ex: Fungi, plants,

animals, etc.

Obtain & Use Energy• Metabolism = combination of

chemical reactions through which an organism builds up or breaks down materials

Grow & Develop

• Grow = to increase in size

• Develop = change in appearance along with growth– “maturation”– EX: Butterflies

begin life as eggs, then become caterpillars, a pupa, and finally emerge as adult butterflies.

Reproduce• Reproduce = produce new organisms of the same type

• Asexual Reproduction– Single organism can

reproduce without aid of another

– Ex: budding (hydra)– Ex: binary fission

(bacteria)• Sexual

Reproduction– Two cells from

DIFFERENT individuals unite to produce new organism

– Ex: humans, plants

Based on a universal genetic code

• Offspring will resemble their parents. – Ex: Flies produce flies, dogs produce

dogs, and seeds from maple trees produce maple trees.

• The genetic code, with a few minor variations, determines the inherited traits of every organism on Earth

• Genetic Code = DNA– Deoxyribonucleic acid

Taken as a group, change over time

• Evolution = group of organisms changing over generations– Ex: Plants that live

in the desert survive because they have become adapted to the conditions of the desert.

Maintain a stable internal

environment• Homeostasis – a living thing’s ability to maintain constant conditions necessary for life– Body temperature: you sweat when

you’re too hot, shiver when you’re too cold

– Blood pH

1-4 Tools and Procedures• How

scientists work…–Lab safety–Metric system

Metric System• Universal system of measurement for

science– Length?

• meter– Volume?

• liter (liquid)• cubic centimeter (solid)

– Mass?• gram

– Temperature?• Celsius scale• Kelvin

Kilo

Hecto

Deka

BASE

Deci

Centi

Milli

Base Units for the Metric System:

• Liters = volume• Meters = distance• Grams = mass

Convert the following using the staircase

• 54.11 deciliters = liters• 47 hectometers = decimeters• 2293 dekagrams = decigrams• 4731 liters = hectoliters• 5912 kilograms = grams• 0.01 grams = milligrams• 0.0108 centimeters =

meters• 3851 milliliters = dekaliters

• 56 hectometers = decimeters

• 94.66 deciliters = liters• 1183 dekagrams =

decigrams• 5842 liters =

hectoliters• 6833 kilograms =

grams• 0.0023 centimeters =

meters• 4967 milliliters =

dekaliters• 0.07 grams =

milligrams

Homework

Microscopes• Compound Light

Microscope– 2-dimensional– Can see LIVING

things.– High magnification

• Able to see cells– Low resolution

• Only magnify 1000 times.

What is magnification?• Magnification is the enlargement in

size of an image.

What is resolution?• Resolution is the clarity of an

image, or the level of detail in the image.

The Parts of the microscope